Testing Coils off bike

[salty_monk]

Anyone know a reliable way of testing coils that aren't connected to the bike?

Thought of maybe powering them up with a spare battery & triggering them to see if I can get spark...

I know you can also measure ohm & continuity but I'm not 100% on what to do with that... anyone advise?

Cheers,

Dan

[rapidray]

The BIGGEST problem with testing coils is that if they are acting up, it will happen AFTER they get hot. If they are cold they will almost always test just fine. I think putting some power to them may be a way to get some heat into them but I don't know how it can be done consistently. Putting power to them without cycling them like the engine is running to DISCHARGE them will cause them to overheat in a hurry. Ray.

[tkent02]

Just a basic functional test, put a spark plug in the wire and ground it, wire the coil to a battery as it is powered on the bike, except scrape one end of the wire along the battery post, the scraping will cause an intermittent connection similar to a set of points operating, you will get sparks at the plug.

But as posted above, this says nothing about how it will function once it gets hot.

[tone]

As ray says coil problems usually appear when they are hot & thats difficult to do with them off the bike

I long ago gave up testing coils for this reason & simply substitute any suspect coils with known good ones to test the theory

tone

[salty_monk]

I just bought a set to put on the shelf with my Dyna S that's also on the shelf... one day I'll get round to fitting them to the skunk instead of points!

Thanks for comments.

Powering them up (to get them hot) & then testing for a short circuit could be another way I guess?

Dan

[don_gibb6512]

The BIGGEST problem with testing coils is that if they are acting up, it will happen AFTER they get hot. If they are cold they will almost always test just fine. I think putting some power to them may be a way to get some heat into them but I don't know how it can be done consistently. Putting power to them without cycling them like the engine is running to DISCHARGE them will cause them to overheat in a hurry. Ray.

+1 on that. I had a set of Accel coils that were failing in the secondary windings after they got hot. Tested fine when cold. Figured it out after running the bike until the coils failed and carried a volt meter with me to test them immediately after the failure.

Needless to say I'm a Dyna man for life now.

Good luck.

[trippivot]

ground the iron core of a ignition coil to a test battery

put positive from the test battery to 1 small coil post with small gauge wire

get a spark plug grounded to the test system hooked up to plug wire in the coil.

ground and un ground the other small ign coil post = spark spark.

to get the coil hot just keep the other small post grounded to the iron core it will heat up in 5 minutes or so. then un-ground it re ground it to check spark.

if the spark plug has a good secure ground you will not get bit.

[salty_monk]

Thanks....

Just a FYI Don Gibb, I have had a Dyna coil go out on me before. They replaced it though even though it was 13 months old.

Dan

[rapidray]

My buddy Larry at Dynatek is a GOOD guy!!! Ray.

[salty_monk]

Sure is...

[don_gibb6512]

Thanks....

Just a FYI Don Gibb, I have had a Dyna coil go out on me before. They replaced it though even though it was 13 months old.

Dan

Another good reason to go Dyna.

[salty_monk]

Sure but the Accel ones are ok too from everything I've read about them. Even stockers are pretty reliable.